/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.jena.sparql.syntax;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.jena.graph.Node;
import org.apache.jena.graph.Triple;
import org.apache.jena.sparql.core.BasicPattern;
import org.apache.jena.sparql.core.Quad;
import org.apache.jena.sparql.modify.request.QuadAcc;
import org.apache.jena.sparql.serializer.FormatterTemplate;
import org.apache.jena.sparql.util.Iso;
import org.apache.jena.sparql.util.NodeIsomorphismMap;

/** Quads/Triples template. */
public class Template {
    static final int HashTemplateGroup = 0xB1;
    private final QuadAcc qp;
    private final BasicPattern bgp;

    public Template(QuadAcc qp) {
        this.qp = qp;
        this.bgp = null;
    }

    public Template(BasicPattern bgp) {
        this.bgp = bgp;
        this.qp = null;
    }

    public boolean containsRealQuad() {
        for ( Quad quad : this.getQuads() ) {
            if ( !Quad.defaultGraphNodeGenerated.equals(quad.getGraph()) ) {
                return true;
            }
        }
        return false;
    }

    public BasicPattern getBGP() {
        if ( this.bgp != null ) {
            return this.bgp;
        }
        BasicPattern bgp = new BasicPattern();
        for ( Quad q : qp.getQuads() ) {
            if ( Quad.defaultGraphNodeGenerated.equals(q.getGraph()) )
                bgp.add(q.asTriple());
        }
        return bgp;
    }

    public List<Triple> getTriples() {
        if ( this.bgp != null ) {
            return this.bgp.getList();
        }
        List<Triple> triples = new ArrayList<>();
        for ( Quad q : qp.getQuads() ) {
            if ( Quad.defaultGraphNodeGenerated.equals(q.getGraph()) )
                triples.add(q.asTriple());
        }
        return triples;
    }

    public List<Quad> getQuads() {
        if ( this.bgp != null ) {
            List<Quad> quads = new ArrayList<>();
            for ( Triple triple : this.bgp.getList() ) {
                quads.add(new Quad(Quad.defaultGraphNodeGenerated, triple));
            }
            return quads;
        }
        return qp.getQuads();
    }

    public Map<Node, BasicPattern> getGraphPattern() {
        List<Quad> quads = getQuads();
        HashMap<Node, BasicPattern> graphs = new HashMap<>();
        for ( Quad q : quads ) {
            BasicPattern bgp = graphs.get(q.getGraph());
            if ( bgp == null ) {
                bgp = new BasicPattern();
                graphs.put(q.getGraph(), bgp);
            }
            bgp.add(q.asTriple());
        }
        return graphs;
    }

    // -------------------------

    private int calcHashCode = -1;
    @Override
    public int hashCode() {
        // BNode invariant hashCode.
        int calcHashCode = Template.HashTemplateGroup;
        for ( Quad q : getQuads() )
            calcHashCode ^= hash(q) ^ calcHashCode << 1;
        return calcHashCode;
    }

    private static int hash(Quad quad) {
        int hash = 0;
        hash = hashNode(quad.getSubject()) ^ hash << 1;
        hash = hashNode(quad.getPredicate()) ^ hash << 1;
        hash = hashNode(quad.getObject()) ^ hash << 1;
        hash = hashGraph(quad.getGraph()) ^ hash << 1;
        return hash;
    }

    private static int hashGraph(Node node) {
        if ( node == null )
            return Quad.defaultGraphNodeGenerated.hashCode();
        if ( node.isBlank() )
            return 59;
        return node.hashCode();
    }

    private static int hashNode(Node node) {
        if ( node == null )
            return 37;
        if ( node.isBlank() )
            return 59;
        return node.hashCode();
    }

    public boolean equalIso(Object temp2, NodeIsomorphismMap labelMap) {
        if ( !(temp2 instanceof Template tg2) )
            return false;
        List<Quad> list1 = this.getQuads();
        List<Quad> list2 = tg2.getQuads();
        if ( list1.size() != list2.size() )
            return false;

        for ( int i = 0; i < list1.size(); i++ ) {
            Quad q1 = list1.get(i);
            Quad q2 = list2.get(i);
            boolean iso = Iso.quadIso(q1, q2, labelMap);
            if ( !iso ) {
                return false;
            }
        }
        return true;
    }

    public void format(FormatterTemplate fmtTemplate) {
        fmtTemplate.format(this);
    }
}
